合成路线1

2) An improved procedure consisted of condensation of 5-nitroisatoic anhydride (I) with beta-alanine ethyl ester (V) to give amide (XIV). The amino group of (XIV) was protected with benzhydryl bromide (VII) yielding (XV), and then the nitro group of (XV) was reduced to aniline (XVI) by catalytic transfer hydrogenation. Protection of the amine of (XVI) as the tert-butyl carbamate (XVIII) was effected using 2-(tert-butoxycarbonyloxymino)-2-phenylacetonitrile (XVII). The sequence of condensation of (XVIII) with bromoacetyl bromide (IX), followed by cyclization of the intermediate bromoacetamide with DBU provided the benzodiazepinedione (XIX). Hydrogenolysis of the N-benzhydryl group of (XIX) in the presence of Pearlman's catalyst, followed by treatment with trimethylsilyl azide furnished the tetrazole (XX). The Boc group of (XX) was deprotected with trifluoroacetic acid, and subsequent coupling with 4-cyanobenzoyl chloride (III) gave amide (XXI). The cyano group was of (XXI) then converted to hydroxyamidine (XXII) with hydroxylamine. Catalytic hydrogenation of (XXII) in the presence of Ac2O and AcOH produced the corresponding amidine. Finally, the ester group was hydrolyzed with LiOH.